Turbine engine rotor wheel with blades made of a composite material provided with a spring ring

1. A turbomachine rotor wheel comprising:

blades of composite material;

an annular mounting plate;

a plurality of composite material blades mounted on the mounting plate by their roots, each blade also including a top platform at its tip carrying radial labyrinth teeth for abrading an abradable material carried by a casing surrounding the wheel;

an orientation disk fastened coaxially around the mounting plate and including at its outer periphery a plurality of axial slots that are open at one end, each slot presenting a cross-section that matches the cross-section of a blade root so as to hold it angularly in position by co-operation of shapes; and

a variable-diameter spring ring housed in part in an axial notch formed in each blade root and projecting axially relative thereto, the spring ring configured to come into radial abutment against an inside surface of the orientation disk during radial outward movement of the blades relative to the mounting plate.

2. A wheel according to claim 1 , wherein the spring ring is made of a material that expands thermally such that its diameter varies as a function of a temperature to which it is subjected.

3. A wheel according to claim 1 , wherein the spring ring is split such that its diameter varies when it is subjected to centrifugal force.

4. A wheel according to claim 1 , wherein the mounting plate includes an outwardly-projecting radial wall at an upstream end, the orientation disk being fastened to the mounting plate against a downstream end thereof.

5. A turbomachine including at least one rotor wheel according to claim 1 .